#include<iostream>
#include<cstring>
using namespace std;
typedef long long LL;
const int N = 5e5 + 10;
int arr[N], temp[N];
int n;
LL merge_sort(int arr[], int l, int r)
{
	if (l == r)return 0;
	int mid = (l + r) >> 1;
	LL ans = merge_sort(arr, l, mid) + merge_sort(arr, mid + 1, r);
	int i = l;
	int j = mid + 1;
	int k = 0;
	while (i <= mid && j <= r) {
		if (arr[i] <= arr[j]) {
			temp[k++] = arr[i++];
		}
		else {
			ans += mid - i + 1;
			temp[k++] = arr[j++];
		}
	}
	while (i <= mid)temp[k++] = arr[i++];
	while (j <= r)temp[k++] = arr[j++];
	for (int i = l, j = 0; i <= r; i++, j++) {
		arr[i] = temp[j];
	}
	return ans;
}
int main()
{
	while (cin >> n) {
		if (!n)break;
		memset(arr, 0, sizeof(arr));
		memset(temp, 0, sizeof(temp));
		for (int i = 0; i < n; i++) {
			cin >> arr[i];
		}
		LL ans = merge_sort(arr, 0, n - 1);
		cout << ans << endl;
	}
	return 0;
}